Natural bentonites-influence of the ion exchange and partial desiccation on permeability and self-healing capacity of bentonites use in GCLs

摘要

Geosynthetic clay liners (GCLs) are sealing elements, which contain natural sodium bentonite encapsulated between geotextile components. They are used in a variety of sealing applications and are most commonly employed to replace compacted clay liners (CCLs). One important field of application is landfill capping systems. In that geochemical environment an ion exchange of sodium-bentonite to calcium-bentonite occurs over a period of approximately 1-3 years, if in contact with cover-soil seepage. As a results, there is a slight increase in hydraulic conductivity of approximately half to one order of magnitude.